Photoelectric meter-scanning apparatus



' y 1951 H. M. JOVHNSON 2,550, 8

PHOTOELECTRIC METER-SCANNING APPARATUS Filed Oct. 25, 1949 4 Sheets-Sheet 1 2% INVENTOR.

JlmeE/ar N. JoH/vso/v y 1951 H. M. JOHNSON 2,550,818

PHOTOELECTRIC METER-SCANNING APPARATUS Filed Oct. 25, 1949 4 Sheets-Sheet 2 [NI 'ENTOR. .flERB-ERT l7. am/501v May 1, 1951 H.M.JOHNSON' PHOTOELECTRIC METER-SCANNING APPARATUS Filed Oct. 25, 1949 IL A l o 0 ix 0 6 g l l l. I

4 Sheets-Sheet 3 HVVENTUR.

M 1, 1951 H. M. JOHNSON 2,550,818

PHOTOELECTRIC METER-SCANNING APPARATUS Filed Oct. 25, 1949 4 Sheets-Sheet 4 11 V INVENTOR.

' 53 JL/ERB'ERT f1 Jan/vs 01v Patented May 1, 1951 OFFICE PHOTOELECTRIC METER-SCANNING APPARATUS Herbert M. Johnson, Needham, Mass.

' Application October 25, 1949, Serial No. 123,355

, 1 I This invention relates to the testing and calibrating of electric meters of the type in which a pivoted element, commonlya flat disc, is associated with counting mechanism by which the rotations of the disc are progressively totaled to indicate current consumption. The function of such scanning apparatus is to accurately record the number of revolutions of the meter disc in a given time interval, as compared to the revolutions of a standard instrument under identical conditions.

In a common type of scanning; apparatus, photo-electric devices indicate the completion of each revolution of the disc by reflecting a beam of light from a polished disc surface, and by' providing a black line or spot on the discwhich interrupts the reflection once in each disc"revo lution. The countin mechanism commonly operates positively during each dark period. The number of interruptions in a given period is then totalled automatically.

In a somewhat difierent apparatus, the counting mechanism is operated positively when a light ray is transmitted to the cathode of a photoelectric cell through a perforation in a revolving opaque disc.

Electric meters are of difierent types and structure, and each type requires a special setting of the light source and of the photo-electric tube to secure accurate performance. It is also necessary that these two instrumentalities have a com- 1 mon focal point on the surface of the rotatin disc.

It is the general object of myinvention to improve the construction of such scanning apparatus by mounting the light source and the photoelectric tube on a common segmental support in such manner that they may each be angularly adjusted on the support but will remain directed to a common focal point in every angularly adjusted position.

Much time and labor is thus saved over previously used apparatus in which the light source and the photo-electric tube were each universally adjustable and had no necessary relation to each other nor to any common focal point except as manually directed.

1 Claim. (01. 250-:234)

2 Fig. 2 is a partial plan View showing certain parts only; Fig. 3 is a side elevation but in partial perspective; I I

Fig. 4 is a longitudinal section of the light source assembly; v

Fig; 5 is an end view thereof;

Fig. 6 is a longitudinal section of the photoelectric tube assembly; and

Fig. 7 is a plan View of a meter disc.

Referring to the drawings, I have shown my improved scanning'apparatus mounted on a casing 0 (Fig. 1) and pivotally supported on a bearing bracket II] which is secured to the top of the casing. An upright post II is clamped in the outer end of a link l2 which in turn is mounted in the outer end of an arm l4 pivoted on a stud I5 in the bearing bracket l 0.

The post Il may thus be supported in any desired vertical position relative to the meter under test, which latter is mounted on a cross-bar l6 (Fig. 1) and which is secured by a roller stud I! on a slide 18 having a clamping knob I9. The slide i8 is mounted in a vertical slot or guideway 20 in the front of the casing C. The meter disc..D is shown in broken lines in Fig. 1 and may have a radial black line N as shown in Fig. 7.

The post Il may be vertically adjusted in the link I2 and is secured by a clutch 22 (Fig. 1) and a clutch nut 23. The post II and clutch 22 are also angularly adjustable in the link l2 and are secured by a clamping nut 24 and lock nut 25.

The link l2 and arm l4 may be fixed relative to each other by a. clamping nut 26, and the arm 14 may be held in fixed position on the stud l5 by a clamping nut 21.

A segmental support 30 is secured to the lower end of the post I l by a clamping stud 3i inserted in a selected one of three holes 32 in the support. The support 30 may also be swung in its own plane on the clamping stud 3|.

It is thus possible to secure the segmental support in any desired relation to the disc D of the meter under test.

The specific means shown and above described for positioning the segmental support 30 may obviously be substantially varied within the scope of my invention.

A light source assembly L and a photo-electric tube assembly T are each mounted on the segmental support 30 and are separately adjustable thereon.

The light source assembly L is positioned on the segmental support 30 by spaced roller studs 40 (Fig. 5) engaging the outer edge of the support 30, and by a roller stud 4| engaging the inner edge. The stud 4| is mounted on a screw 42 which also secures a clamping plate 43 against the back face of the support 30.

The light source assembly L may thus be secured in any selected angular position on the segmental support 30, and the spaced studs 40 will direct the light beam to the center of curvature of the"support' '30.

The tubea'ssembly T (Fig. 6) is s'imilarly'provided with spaced studs 50 and a coacting roller stud 5|, clamping screw 52 and clamping plate 53. The spaced studs 50 center-the tubeaassem bly T on the center of curvature of the support 30, which center thus serves as a common focal point for the light assembly L and "thetube assembly T.

The light assembly L (Figs. 4 and5) comprises a tube 60, light bulb 6|, lens 62, cooling fins 63 and flexible connection'i64. The tube 60 is preferably perforated' for cooling.

The tube assembly T (Fig. 6) has 'aitube-lfl, photo-electric unit ll ,ilens "712 Sand flexible--connection 73. The details of constructionmof -the assembliesxL and T -f0rm;n01:-pa1t of thezpresent invention.

Having described the detailed structure ofsmy invention; the use :and advantages thereof T"Wi11 be readily apparent. :ThesegmentaL-support-SO and assemblies Lland T comprisea -unitiin which the assemblies Land ;T are-angularlyseparately adjustable, but the two assemblies always remain inthe :sa-mev plane :tnormal to: the :axis of the support-30=and are both always centered-on said .axis.

. Furthermore, the above-defined unit may-be shifted about to anydesired; position to. secure clear vision of the rotatingdisc- D,-,and.may be securely -heldinany such r-position.

Adaptation of the scanning apparatus to vary ing meter constructions is thus easily performed and much time is saved by providing a common and permanently located focal point for the two separate assemblies L and T.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as s'etfdrth in'the claim; but'what'l claim is:

"In'-"-aphoto electric meter scanning apparatus having a light source assembly and a photo-electrio tube assembly, that improvement which comprises-.providing a common support for said stwolaassemblies in the form of a segmental plate,

means to adjustably secure said assemblies on saidsupportrmeans to maintain a common focal s pointfor saidassemblies, each assembly having two spaced postioning rolls engaging one edge ofsai'd segmental plate and having a single positioning roll engaging the other edge of said plate, unitary" means -to :rotatablyfsupport: :said single rolland ='tocla-m-p 'said assembly :to said segmental plate in-zany adjustedposition 1 thereof but-leaving said single: roll. .fr-eevto: rotate, and 7 universal means-.cbeing provided to:- mount u said segmental plate :.-for adjustment to ;.anyselected upright positionin said=apparatus.

-I-IERBERT J QHN SON :REEERENGES CITED The following references are of recordQini-the file ofithis patent:

' UNITED "STATES PATENTS Number I Name 7 Date --1.,853,657 sBradshaw-etal Apr. 12,1932 v.2,4 06,-166 -Scott -i Aug..20, 1946 21,457,133 Alden -.Dec. 28,1948 2,535,001 -Truesdell Dec. 19,,1950 

